diff --git a/atrcopy/dos33.py b/atrcopy/dos33.py
index 11ae98c..f0a8391 100644
--- a/atrcopy/dos33.py
+++ b/atrcopy/dos33.py
@@ -524,8 +524,14 @@ class Dos33DiskImage(DiskImageBase):
 class ProdosHeader(Dos33Header):
     file_format = "ProDOS"
 
+    def __str__(self):
+        return "%s Disk Image (size=%d) THIS FORMAT IS NOT SUPPORTED YET!" % (self.file_format, self.image_size)
+
+
+class ProdosDiskImage(DiskImageBase):
+    def __str__(self):
+        return str(self.header)
 
-class ProdosDiskImage(Dos33DiskImage):
     def read_header(self):
         self.header = ProdosHeader()